Address

An address is a string of letters and numbers that identifies a destination for cryptocurrency payments — the account identifier you share when you want to receive funds. Addresses are derived mathematically from a public key, which in turn pairs with a private key that only the owner holds. Anyone can send to an address, but only the holder of the corresponding private key can spend from it.

Each blockchain has its own address format. Bitcoin addresses come in several styles, including newer ones beginning with "bc1"; Ethereum addresses are 42 characters starting with "0x", such as 0x71C7656EC7ab88b098defB751B7401B5f6d8976F. For example, to receive ether, you copy your wallet's address and give it to the sender — the payment then appears on the blockchain, visible to anyone who looks that address up on a block explorer.

A common misconception is that addresses are private; every address's full transaction history and balance are publicly visible on the blockchain, so addresses are pseudonymous rather than anonymous, and reusing one address links all its activity together. Two practical warnings follow from how addresses work. First, transactions are irreversible — funds sent to a mistyped or wrong-network address are usually lost, so many users send a small test amount first. Second, malware can swap addresses in your clipboard, so always verify at least the first and last several characters before confirming a transaction.